import 'dart:io';

import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:miler/data/proof_store.dart';
import 'package:miler/data/service_profile.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// PROOF OF DELIVERY
///
/// A photo taken at a door is evidence, and evidence that disappears is worse
/// than none — it makes the rider believe he has cover he does not have.
/// These pin the two properties that make it real: it outlives the OS cache
/// `ImagePicker` hands back, and it belongs to the session that took it.
/// ─────────────────────────────────────────────────────────────────────────
void main() {
  late Directory docs;

  setUp(() async {
    ServiceProfile.setActive(ServiceProfile.milkMan);
    SharedPreferences.setMockInitialValues({'userid': 38});

    // path_provider has no host under the test binding.
    docs = await Directory.systemTemp.createTemp('proof_docs');
    TestWidgetsFlutterBinding.ensureInitialized();
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(
          const MethodChannel('plugins.flutter.io/path_provider'),
          (call) async => docs.path,
        );
  });

  tearDown(() async {
    ServiceProfile.setActive(ServiceProfile.parcel);
    if (await docs.exists()) await docs.delete(recursive: true);
  });

  /// A real 1×1 PNG. The store tests never decode it, but the widget test
  /// does: `Image.file` on 64 bytes of nonsense never completes its frame, so
  /// `pumpAndSettle` waits for a decode that will never land and the test
  /// hangs for the full ten minutes rather than failing.
  const List<int> onePixelPng = [
    0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, //
    0x00, 0x00, 0x00, 0x0D, 0x49, 0x48, 0x44, 0x52,
    0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
    0x08, 0x06, 0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4,
    0x89, 0x00, 0x00, 0x00, 0x0A, 0x49, 0x44, 0x41,
    0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00,
    0x05, 0x00, 0x01, 0x0D, 0x0A, 0x2D, 0xB4, 0x00,
    0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE,
    0x42, 0x60, 0x82,
  ];

  /// Stands in for what the camera hands back: a file in a volatile place.
  Future<File> cameraShot(String name) async {
    final cache = await Directory.systemTemp.createTemp('picker_cache');
    final f = File('${cache.path}/$name.jpg');
    await f.writeAsBytes(onePixelPng);
    return f;
  }

  group('the store', () {
    test('the photo is copied out of the camera cache', () async {
      final shot = await cameraShot('a');
      final saved = await ProofStore.save('ORDER-1', shot.path);

      expect(saved, isNotNull);
      expect(
        saved,
        isNot(shot.path),
        reason:
            'ImagePicker returns an OS cache path the system reclaims — '
            'a record pointing at it loses its evidence',
      );
      expect(File(saved!).existsSync(), isTrue);

      // The original can vanish and the proof survives, which is the point.
      await shot.parent.delete(recursive: true);
      expect(File(saved).existsSync(), isTrue);
      expect(await ProofStore.pathFor('ORDER-1'), saved);
    });

    test('a retake replaces rather than accumulates', () async {
      final first = await ProofStore.save(
        'ORDER-1',
        (await cameraShot('a')).path,
      );
      final second = await ProofStore.save(
        'ORDER-1',
        (await cameraShot('b')).path,
      );
      expect(second, first, reason: 'one stop, one proof');
      expect(await ProofStore.pathFor('ORDER-1'), second);
    });

    test('a proof whose file has gone is not proof', () async {
      final saved = await ProofStore.save(
        'ORDER-1',
        (await cameraShot('a')).path,
      );
      await File(saved!).delete();
      expect(
        await ProofStore.pathFor('ORDER-1'),
        isNull,
        reason: 'returning a dead path would draw a broken image as evidence',
      );
    });

    test('nothing is invented from nothing', () async {
      expect(await ProofStore.save('', 'whatever'), isNull);
      expect(await ProofStore.save('ORDER-1', ''), isNull);
      expect(await ProofStore.save('ORDER-1', '/no/such/file.jpg'), isNull);
      expect(await ProofStore.pathFor('ORDER-NONE'), isNull);
    });

    test('a device path is never offered as a remote url', () async {
      await ProofStore.save('ORDER-1', (await cameraShot('a')).path);
      expect(
        await ProofStore.remoteUrlFor('ORDER-1'),
        '',
        reason:
            'the Miler API has no upload route; a filesystem path written '
            "into the hub's photourl would look like evidence and resolve to "
            'nothing',
      );
    });
  });

  group('ownership', () {
    test("another rider cannot open this rider's doorstep photos", () async {
      await ProofStore.save('ORDER-1', (await cameraShot('a')).path);
      expect(await ProofStore.pathFor('ORDER-1'), isNotNull);

      SharedPreferences.setMockInitialValues({'userid': 99});
      expect(
        await ProofStore.pathFor('ORDER-1'),
        isNull,
        reason: 'proof is scoped like every other record — see WorkScope',
      );
    });

    test('the other line cannot either', () async {
      await ProofStore.save('ORDER-1', (await cameraShot('a')).path);
      ServiceProfile.setActive(ServiceProfile.parcel);
      expect(await ProofStore.pathFor('ORDER-1'), isNull);
    });

    test('logout deletes the photos, not just the index', () async {
      final saved = await ProofStore.save(
        'ORDER-1',
        (await cameraShot('a')).path,
      );
      await ProofStore.clearScope();

      expect(await ProofStore.pathFor('ORDER-1'), isNull);
      expect(
        File(saved!).existsSync(),
        isFalse,
        reason: "a doorstep photo must not outlive the session that took it",
      );
    });
  });
}